Chen Xiao, Shi Chuang, Wang Xing-Bao, Li Wen-Ying, Liang Changhai
State Key Laboratory of Fine Chemicals, Laboratory of Advanced Materials and Catalytic Engineering, School of Chemical Engineering, Dalian University of Technology, Dalian, 116024, China.
State Key Laboratory of Clean and Efficient Coal Utilization, Taiyuan University of Technology, Taiyuan, 030024, China.
Commun Chem. 2021 Dec 13;4(1):175. doi: 10.1038/s42004-021-00612-0.
Designing highly active and stable lead-free palladium-based catalysts without introducing surfactants and stabilizers is vital for large-scale and high-efficiency manufacturing of cis-enols via continuous-flow semi-hydrogenation of alkynols. Herein, we report an intermetallic PdZn/ZnO catalyst, designed by using the coupling strategy of strong electrostatic adsorption and reactive metal-support interaction, which can be used as a credible alternative to the commercial PdAg/AlO and Lindlar catalysts. Intermetallic PdZn nanoparticles with electron-poor active sites on a Pd/ZnO catalyst significantly boost the thermodynamic selectivity with respect to the mechanistic selectivity and therefore enhance the selectivity towards cis-enols. Based on in situ diffuse reflectance infrared Fourier-transform spectra as well as simulations, we identify that the preferential adsorption of alkynol over enol on PdZn nanoparticles suppresses the over-hydrogenation of enols. These results suggest the application of fine surface engineering technology in oxide-supported metal (particles) could tune the ensemble and ligand effects of metallic active sites and achieve directional hydrogenation in fine chemical synthesis.
在不引入表面活性剂和稳定剂的情况下设计高活性和稳定的无铅钯基催化剂，对于通过炔醇的连续流半加氢大规模高效制备顺式烯醇至关重要。在此，我们报道了一种金属间化合物PdZn/ZnO催化剂，它是通过强静电吸附和活性金属-载体相互作用的耦合策略设计而成的，可作为商业PdAg/AlO和林德拉催化剂的可靠替代品。在Pd/ZnO催化剂上具有贫电子活性位点的金属间化合物PdZn纳米颗粒显著提高了相对于机理选择性的热力学选择性，从而增强了对顺式烯醇的选择性。基于原位漫反射红外傅里叶变换光谱以及模拟，我们确定炔醇在PdZn纳米颗粒上比烯醇优先吸附抑制了烯醇的过度氢化。这些结果表明，精细表面工程技术在氧化物负载金属（颗粒）中的应用可以调节金属活性位点的集合和配体效应，并在精细化学合成中实现定向氢化。
